4+
Years Experience
Backend-heavy product delivery
Available for Work
MERN Stack Developer
BUILDING BOLD PRODUCTS
KUNAL SINGH.
— Full-Stack MERN Developer building backend-heavy web products with Node.js, React & Next.js
KUNAL SINGH.
I build backend-heavy web products that stay fast, stable, and easy to evolve.
Across four years, I have shipped full-stack systems spanning commerce, CRM, logistics, and conversational automation.
Node.jsExpress.jsTypeScriptReact.jsNext.jsMySQLMongoDBPostgreSQLAWS EC2AWS S3Socket.ioPayment GatewaysMQTT
6
Products Shipped
Case studies across multiple domains
9.33
GPA
B.Sc. IT, University of Mumbai
10+
Integrations Built
PayU, Razorpay, MQTT, Zoom, Facebook, WhatsApp, IVR...
KS
About
Building products from idea to impact.
About Me
I am a MERN stack developer based in Thane, Mumbai, focused on shipping product experiences that balance frontend polish with strong backend architecture.
My work usually sits close to the business: payments, CRM automation, workflow systems, real-time communication, and operational tooling that teams rely on every day.
I enjoy owning the full delivery path from API and database design through UI implementation, deployment, and production hardening.
I specialize in building production-grade backend systems — from payment gateway integrations (PayU, Razorpay) to real-time communication tools using Socket.io and MQTT. Whether it's a SaaS platform, CRM, or e-commerce system, I focus on architecture that scales cleanly as the product grows.
Featured Projects
Case studies built around backend depth, real integrations, operational workflows, and production surfaces that stay clear under pressure.
8 of 8 Projects
What I Do
Services Built for Scale
Backend-heavy product engineering for startups and businesses that need reliable systems, not just pretty interfaces. From architecture to deployment, I own the full delivery path.
4+ YearsProduction Experience
6+ ProductsShipped End-to-End
10+ IntegrationsPayment & Communication
100% RemoteGlobal Delivery
Custom Web Development
Modern, scalable websites and web applications designed to increase conversions and accelerate business growth.
- Business Websites
- Custom Web Applications
- Admin Dashboards
React.jsNext.jsNode.js
Learn moreMobile App Development
Cross-platform Android and iOS applications with beautiful UI and reliable backend integrations.
- Android & iOS
- React Native
- API Integration
React NativeNode.jsMongoDB
Learn moreCustom ERP & Business Management Systems
Custom ERP software that automates operations, improves productivity, and centralizes your business data.
- CRM
- Inventory
- Sales & Purchase
ReactNext.jsNode.js
Learn moreSaaS Product Development
Build and launch scalable SaaS platforms with secure authentication, subscriptions, and cloud infrastructure.
- Subscription Billing
- Authentication
- Tenant Management
Next.jsNode.jsPostgreSQL
Learn moreAPI Development & Third-Party Integrations
Secure APIs and seamless integrations connecting your business with external platforms.
- REST APIs
- Payment Gateways
- WhatsApp API
Node.jsExpress.jsJWT
Learn moreDedicated Developer / Hourly Freelancing
Flexible development support for startups, agencies, and businesses on an hourly basis.
- Feature Development
- Bug Fixes
- Consulting
ReactNext.jsNode.js
Learn moreHave a project in mind? Let's discuss how I can help.
View All ServicesSkills & Technologies
Backend Engineering
Building resilient APIs, business logic, and integration-heavy systems that support real product operations.
Node.js
Express.js
REST APIs
Socket.io
Frontend Development
Crafting responsive interfaces with modern React patterns and product-focused interaction design.
React.js
Next.js
React Flow
TypeScript
Databases
Designing and working with data models that support speed, clarity, and operational reliability.
MySQL
MongoDB
PostgreSQL
Cloud & Deployment
Shipping production-ready applications with dependable infrastructure and hosting workflows.
AWS EC2
AWS S3
SSL & Hosting
Deployment Ops
Languages
Using the right language for product engineering, systems thinking, and implementation depth.
JavaScript
TypeScript
C
C++
Experience
May 2022 - Present
MERN Stack Developer
Sublime TechnoCorp
- Architected and shipped 5+ full-stack products across e-commerce, CRM, digital signage SaaS, and logistics — owning backend design, API development, and frontend delivery end-to-end.
- Designed production-grade REST APIs and database schemas across PostgreSQL, MySQL, and MongoDB, leveraging stored procedures, triggers, and database functions for business-critical workflows.
- Integrated payment gateways (PayU, Razorpay) with split-payment logic, coupon validation, and real-time pricing engines driven by live market data.
- Built multi-channel integrations across Facebook Business SDK, WhatsApp API, IVR, IndiaMART, JustDial, MQTT, and Zoom Video SDK for automation and real-time communication.
- Managed end-to-end production infrastructure — Ubuntu VPS provisioning, SSL certification, AWS EC2/S3 deployment, and CI/CD pipelines via GitHub Actions.
Education
MCA
Manipal (Online)
8.14
B.Sc. IT
University of Mumbai
Built a strong academic foundation in software development, data handling, and applied computing.
GPA 9.33/10
HSC
Gandhi Nagar Public School, CBSE
SSC
Gandhi Nagar Public School, CBSE
LET'S
TALK.
Open to product engineering roles and contract work — remote or on-site — where backend reliability and thoughtful frontend execution both matter.